// 这里的代码说白了就是干了一件事，通过用户的权限和之前在router.js里面asyncRouterMap的每一个页面所需要的权限做匹配，最后返回一个该用户能够访问路由有哪些。
import { asyncRoutes, constantRoutes } from "@/router";
/**
 * Use meta.role to determine if the current user has permission
 * @param roles
 * @param route
 */
function hasPermission(roles, route) {
  if (route.meta && route.meta.roles) {
    return roles.some(role => route.meta.roles.includes(role));
  } else {
    return true;
  }
}

/**递归过滤异步路由表，返回符合用户角色权限的路由表
 * Filter asynchronous routing tables by recursion
 * @param routes asyncRoutes
 * @param roles
 */
export function filterAsyncRoutes(routes, roles) {
  const res = [];

  routes.forEach(route => {
    const tmp = { ...route };
    if (hasPermission(roles, tmp)) {
      if (tmp.children) {
        tmp.children = filterAsyncRoutes(tmp.children, roles);
      }
      res.push(tmp);
    }
  });

  return res;
}

const state = {
  routes: [], // constantRoutes
  addRoutes: []
};

const mutations = {
  SET_ROUTES: (state, routes) => {
    state.addRoutes = routes;
    state.routes = constantRoutes.concat(routes);
  }
};

const actions = {
  generateRoutes({ commit }, roles) {
    return new Promise(resolve => {
      let accessedRoutes;
      if (roles.includes("admin")) {
        accessedRoutes = asyncRoutes || []; // 如果是admin 直接加载所有路由 超级管理员
      } else {
        // 否则 在根据用户的权限和异步路由表   生成最终可以访问的  路由表
        accessedRoutes = filterAsyncRoutes(asyncRoutes, roles);
      }
      commit("SET_ROUTES", accessedRoutes);
      resolve(accessedRoutes);
    });
  }
};

export default {
  namespaced: true,
  state,
  mutations,
  actions
};
